TITLE:
Evaluation of the Coagulating Potential of the Crude Extract from the Barbatimão Bark for the Treatment of Dairy Effluents
AUTHORS:
Vanuzia Rodrigues Fernandes Ferreira, Josefina Aparecida de Souza, Maria das Graças Cardoso, Luiz Gustavo de Lima Guimarães, Rafaela Magalhães Brandão, Rafaela Vieira Souza, Luana Isac Soares, Jéssica Oliveira e Nogueira, Francielli D’Carlos Cravo, David Lee Nelson
KEYWORDS:
Stryphnodendron adstringens, Acacia mearnsii, Tannins
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.13,
September
6,
2016
ABSTRACT: The coagulating potential of the crude extract from
the barbatimao bark for the treatment of dairy effluent was assessed and
compared with industrial coagulants such as aluminum sulfate (inorganic
coagulant), the crude extract of black wattle bark (used in the manufacture of
natural organic coagulants), and gallic acid (the main constituent of condensed
tannins). The aqueous extract of barbatimao was obtained by refluxing for 12 h,
and the black wattle was provided by a producer of natural coagulants. The determinations
of total phenolic compounds and tannins in the extracts were performed by the
Folin-Ciocalteu method and precipitation with casein, respectively. The treatment
of the effluent with coagulant was performed by the Jar-Test. After testing,
the effluent was evaluated for turbidity, total solids, and biochemical oxygen
demand (BOD). A higher content of phenolic compounds (19.81% mg of gallic
acid/g extract) was observed in the barbatimao extract than in the black wattle
extract (14.24% mg of gallic acid/g extract). However, the extracts contained
the same amount of tannins, 13.95% for the barbatimao extract and 12.89% for
the black wattle extract. A 63%, reduction in BOD was observed for the effluent
treated with barbatimao extract, 35% for the black wattle extract, 58% for
gallic acid and 60.59% for the treatment with aluminum sulfate. Treatment with
gallic acid caused a 98% reduction in the turbidity of the effluent; with
aluminum sulfate, a 97% reduction was
obtained; with barbatimao extract, 96%, and with black wattle extract, 93%.
The barbatimao extract was shown to be a potential coagulant for dairy effluents.